Russia Meteor, Earth is not safe after all

People of Russia near in the incident area were astonished at first seeing a huge fireball over Southern Russia. Witnesses thought of a meteor shower that will just pass over earth and they were shocked when it was striking towards them.

Window glasses and windshields blew out when the meteor exploded causing 250 people an injury,wounds and cuts. Watch the CNN and the RAW video for more details.

This happening has drawn a question to me and to thousands out there. Is earth not SAFE anymore from foreign invaders such this?